Predictive Value of Cardiopulmonary Exercise Testing Parameters in Ambulatory Advanced Heart Failure.

Objectives: This study sought to determine cardiopulmonary exercise (CPX) predictors of the combined outcome of durable mechanical circulatory support (MCS), transplantation, or death at 1 year among patients with ambulatory advanced heart failure (HF).
Background: Optimal CPX predictors of outcomes in contemporary ambulatory advanced HF patients are unclear.
Methods: REVIVAL (Registry Evaluation of Vital Information for ventricular assist devices [VADs] in Ambulatory Life) enrolled 400 systolic HF patients, INTERMACS (Interagency Registry for Mechanically Assisted Circulatory Support) profiles 4-7. CPX was performed by 273 subjects 2 ± 1 months after study enrollment. Discriminative power of maximal (peak oxygen consumption [peak VO ₂ ]; VO ₂ pulse, circulatory power [CP]; peak systolic blood pressure • peak VO ₂ ], peak end-tidal pressure CO ₂ [PEtCO ₂ ], and peak Borg scale score) and submaximal CPX parameters (ventilatory efficiency [VE/VCO ₂ slope]; VO ₂ at anaerobic threshold [VO ₂ AT]; and oxygen uptake efficiency slope [OUES]) to predict the composite outcome were assessed by univariate and multivariate Cox regression and Harrell's concordance statistic.
Results: At 1 year, there were 39 events (6 transplants, 15 deaths, 18 MCS implantations). Peak VO ₂ , VO ₂ AT, OUES, peak PEtCO ₂ , and CP were higher in the no-event group (all p < 0.001), whereas VE/VCO ₂ slope was lower (p < 0.0001); respiratory exchange ratio was not different. CP (hazard ratio [HR]: 0.89; p = 0.001), VE/VCO ₂ slope (HR: 1.05; p = 0.001), and peak Borg scale score (HR: 1.20; p = 0.005) were significant predictors on multivariate analysis (model C-statistic: 0.80).
Conclusions: Among patients with ambulatory advanced HF, the strongest maximal and submaximal CPX predictor of MCS implantation, transplantation, or death at 1 year were CP and VE/VCO _2, respectively. The patient-reported measure of exercise effort (Borg scale score) contributed substantially to the prediction of outcomes, a surprising and novel finding that warrants further investigation. (Registry Evaluation of Vital Information for VADs in Ambulatory Life [REVIVAL]; NCT01369407).
Competing Interests: Funding support and Author Disclosures Supported by U.S. National Institutes of Health, National Heart, Lung, and Blood Institute (NHLBI) contract HHSN268201100026C, and National Center for Advancing Translational Sciences grant UL1TR002240. The views expressed in this manuscript are those of the authors and do not necessarily represent the views of the National Heart, Lung, and Blood Institute (NHLBI), National Institutes of Health, or the US Department of Health and Human Services. Dr. Lanfear has received research grants from NHLBI (R01HL132154), Amgen, Bayer, and Janssen; and is a consultant for Amgen, Janssen, Ortho Diagnostics, and Novartis. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.
(Copyright © 2021 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)